Kristoff, Son of Trolls
by Dagron
Summary: An exploration of the Exolvo universe from Kristoff's perspective... The boy with the flying reindeer and a family of trolls.
1. First meeting

Author's note: Once again this is written with the Frozen-Harry Potter crossover "Exolvo" head cannons in mind. If you are lost, you'll find a link to the master post on tumblr on my profile. There's lots of folk crafting amazing stuff for this setting, well worth a look both at the master post & in the tag where new creations (stories, art, ideas) get shared.

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><p>Part 1: <strong>First meeting<strong>.

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><p>It was a late autumn evening when we first met. I could feel the magnetic pull of the aurora in my joints, but you couldn't see the lights from Saint Mungo's Hospital. Too many illuminations, too many ceilings, and most importantly, too many patients: it was enough to wear an old troll down. It had been a long day, as they tend to go. I was just finishing off, my daughter Bulda fussing in my office, when a wizard, one of the important ones, knocked on my door and asked if I could spare just five more minutes of my time.<p>

"He's already late for the family reunion by fifteen minutes, what does-" I shushed Bulda, raising my hand. I considered this Dumbledore an ally of weight for our kind. It would not do to give him cheek. She rolled her eyes, but became quiet.

"What can I do for you?" I asked, stroking my beard of straw. I looked him up and down, trying to sense the seriousness of the situation. Dumbledore was not the sort to idly ask for help. His eyelids looked heavy with fatigue, but that was not unusual. Most wizards that were as highly regarded as him were hard workers always trying to squeeze the most out of their time. What was unsettling was the way he muttered slightly under his breath, his eyes constantly flicking back to something in the corridor behind him. Something was worrying him, and by the sag of his shoulders, I could tell that whatever had happened saddened him.

They say trolls can't read people. Hah! It is people who can't read trolls.

Dumbledore didn't take any notice of Bulda as she rolled out onto the small balcony adjacent to my room. More of a cupboard than an office, it was the luxury of being able to slip out for a brief breath of fresh air that kept me from asking for any other room. Taking off his glasses, the wizard before me rubbed at the bridge of his nose.

"What is it Albus?" I asked, hobbling closer. He wasn't usually one to be slow with his words.

"I… I'm going to need you to change a young girl's memories for me."

I tilted my head, waiting for him to elaborate. It wasn't an unusual request. Memory alteration was my specialty; it was what gave me the position here at Saint Mungo's hospital for the magically injured in the first place. Rare was the day when I wasn't required to alter some patient's memory for their protection or wellbeing.

"Her happy memories…"

"Oh." I frowned, confused, but not off put. I knew that my old ally would not request this of me without a good reason. "Happy memories of what exactly? And what to..?"

"Wandless magic," he whispered, putting back on his specs and hiding his eyes. "Ice and snow, as far as I can tell. Keep… Keep the memories happy, but the child is not to know that the element was summoned by her sister."

Eyes wide, I paused a moment. Wandless magic was such a broad term. I had to ask.  
>"The sister… Born or… cursed?"<p>

"Born."

Hearing that word was a balm to my old heart. Children born with wandless magic were a gift to the world, no matter how dangerous they could become. Wandless magic born of a curse would be a completely different landslide to deal with.

"Bring the child through." I nodded, hobbling towards the small examination table opposite my desk. I could hear Bulda muttering as she rolled into a ball outside, the cold breeze from the door giving my tired bulk a second wind.

"Thank you, Pabbie," opening the door and waving the family through, Albus Dumbledore nodded gravely before departing. "I shall leave you to it. I have some quill-pushers to handle."  
>I did not envy him the task of sorting out the paperwork for an incident like this.<p>

The second wind from the balcony was much needed. The child came in sound asleep in the arms of her mother. No older than five, she had a lock of hair amongst the shock of ginger that shone white as ice. She'd obviously been partially treated already, my hand tingling as it passed over her right eye from the magical residue. It had been a close call. My heart sank as I noticed the sibling, only a couple of years older, shrunk in upon herself by the doorframe, huddled against her father's legs. It was clearly an accident… Oh, how many families had ended up in these very corridors after a tragically unforeseen mishap?

My features remained stoic as I waved my hands in the air, summoning out the memories that required my touch. I needed to focus. The memories I had to change were multiple and deeply ingrained.

Humans remember fear and pain strongly, sometimes to a debilitating degree. I was used to fighting memories that would not be forgotten. I have lost count the amount of times I've had to hunt out a happy memory so nearly forgotten in order to knock the bad ones loose. This girl, this Anna, she…

Altering all these memories of her and her sister playing, it was like trying to uproot a mountain. The scenes in her mind of snow play and fun were all so full of love and trust; it was a true testament to the beauty that had always drawn me to humans… despite their many tragedies.

Fortunately, most of the memories were easily enough altered: a small tweak of the décor here, an added detail there and another removed from this one… The hardest to change was the last, the one where the infant's joy had reached its crescendo before a blast of cold suddenly turned off the lights. I gripped my crystals to power through. This memory could not be changed. This memory would need to be locked away, somewhere safe. It needed put where it couldn't be reached lest it caused the girl physical harm anew.

Remembering the Pensieve I had helped Dumbledore restore, I wrestled the recollection of the incident into a silvery thread. It glowed, golden light showing how bright and warm it had made the girl feel, the blue tip at the end the only indication that things had gone sour. Ripping a vial from the cord around my waist, I downed its magical contents before using the crystal container on the last memory. It fought and lashed out, but somehow I managed to get it in, flowing smooth and silky, the line to the girls mind pulled taught until I cut the memory loose.

It had taken more than five minutes. Bulda was going to give me an earful.

Leaning against my stool as I dropped down to the floor, the only thing that remained for me to do was to find a safe place for the vial. It glowed still, as golden as the magical energies I kept stored upon my belt. My elbows ground painfully, reminding me exactly how long a day I'd had.

We trolls are very particular about memories. You could say we're particularly possessive: a memory only ever belongs to one person. No two points of view are alike. If one has to be taken away from its owner, it needs to be in the care of the person they'd trust the most with it. After seeing the memories I had just sifted through, I had no doubts.

"She'll be alright," I said, nodding to the mother as the girl shifted into a more comfortable sleeping position, a small smile on her face. She would be having pleasant dreams for a while, as her mind adjusted to the changes I'd wrought. Hobbling towards the door I bowed politely to the father, before turning to the other daughter. She was anxious and tired, it was easy to tell. A thin layer of frost had formed around her feet. "Elsa, I would like you to keep this."

"Is… Is it?" Hesitantly she allowed herself to unclasp one of her hands from her chest, her father squeezing her shoulder in reassurance.

"This is her memory of your magic, yes." Taking her hand in mine as I gently put the crystal in it, I focused on her face, willing my stony features to express the seriousness I truly felt. Her father had knelt down behind her, his face hopefully a good mirror of mine. "I can trust none but you to keep this safe."

"She won't remember my magic?" So young a girl, the blonde's voice sounded weak as she realized exactly what this meant.

"No. She won't. You'll need to keep your powers hidden." Her eyes were cast down as I confirmed what she feared. I continued however, feeling the need to reassure her somewhat. "There is great beauty in your Magic, Elsa, but great danger also. You'll need to learn control."

"We'll help her." Her father agreed, hazel eyes flashing with protective ferocity.

As the family left my office, I felt heavy and weary, wearier than I had felt since I had moved my family here from Scandinavia. Only the small thank you I heard whispered as they left helped me feel lighter over what had just transpired.

"Wow…" The small voice of a boy expressing admiration was not what I had expected to turn around to.

"Bulda, what?"

Bulda was now standing at the door to the balcony, a small blond boy standing before her and what looked like a young reindeer behind. The boy, his clothes a tattered mess of rags and castoffs, gave a shy wave.

"Look at these cuties. Can we keep them?"

The boy didn't say much as my daughter gave him a bone crushing hug.

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><p><strong>(End Part 1)<strong>


	2. Troll magic

Part 2: **Troll Magic**

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><p>It was strange, young Kristoff thought, how much one's life can be turned upside down in one day… Not that this hadn't occurred to him before, but still, one gets accustomed to things being a certain way. Change was always somewhat alien and brutal.<p>

Like going from living on the streets, scrapping meals together from leftovers and handouts, to being taken in by a family of stone people… Like being told by one's father to fly away on the smallest reindeer of the herd and not turn back… That had felt like years ago. He couldn't even remember his parents' names. They were just papa and mama now, hazy recollections from a time too innocent to be true.

Now… Well now he was surrounded by names. They were so very many and new and exciting and he'd already met Bulda and Granpabbie and…

"Oh man, Sven, this is amazing!"  
>His best friend nodded enthusiastically, his tail wagging energetically as he bounced from one member of this big family to the other.<p>

Kristoff laughed happily as a small rock, barely the size of a football, rolled up to him, before leaping up to form a stocky child of stone. He let it pull at his top, and knelt down so that he could rub his hand on the stone-kid's moss like hair. More rock-children appeared, grassy tunics adorned with the odd glowing crystal. He took a moment to admire them. He had never seen the like before. Who could imagine that rocks could not only move and roll, but also leap and play and laugh and sing?

He didn't get much time to admire them. They were intent on getting him to play and wanted to teach him a game they referred to as Klinky Cool Air. Despite the late hour and his tiredness, he was up for it. It would certainly help pass the time until Sven had gotten his fill of licking the bigger stone-folk's faces… Not that the stone-folk seemed to mind. As far as Kristoff could tell, they found it quite endearing.

And it was so that after what seemed to be several hours of playing a giant full on version of marbles that the young boy collapsed, exhausted but happy, Sven the reindeer a content furry pillow for his friend, sharing in dreams of belonging for the first time in a while.

Kristoff later woke up to the sound of voices talking softly, the clearing around him full of dormant rocks, their uncanny roundness the only clue that he hadn't imagined all this. Rubbing blearily at his eyes, he made no effort to sit up. He was comfortable, and he wanted the time to take stock, get his bearings now that the initial euphoria had worn off.

Could he really stay with these rock-people? They were definitely better than people-people… but could he trust them?

He pondered his fortune in getting to meet them in the first place. What had it been that had led the two here? Ah yes, that's right. Ice.

He grinned. Ice always reminded him of happier times. Oh sure, it was a pain when you were sleeping under the stars and struggling to keep warm, but luckily he had Sven and a few tricks he had learnt to deal with that. So long as you had plenty dry layers of clothing, a hat, could find somewhere dry and big enough to allow Sven to kneel down, you could make do, for a little while. It was certainly a bonus if you could find some dry wood and light a fire, or even some paper and card. Kristoff still treasured the little tinderbox he kept in his pouch. He had lost count of how many times he'd resorted to using it, fingers numb from the cold only for it to bring near instant relief, if only by its shimmering light.  
>But ice, man, ice…<p>

Ice for him meant something that would keep food fresh, something to skip over that would slow bad people down. Ice meant a blanket of sparkly diamond dust covering everything with beauty, dazzling and mesmerizing. It meant fun and play that Sven always seemed to enjoy as much as he did, reaching out to catch snowflakes on his tongue, skidding across the slippery surface in a race or rolling around until they both looked like shaggy ice monsters. It also made for an easy source of water, parching a throat often dry from long treks across town and country. Ice was cold, dangerous, but so very beautiful.

Ice to him would always feel like home.

So when Kristoff had seen a trail of it forming behind a dark silhouette in the sky, he hadn't thought twice. Clambering atop Sven, he encouraged the reindeer to take off, his hooves wavering in mid air as the young calf fought to find his balance. They didn't fly often, and when they did it always took Sven a while to get going… But once they were, to Kristoff they were unstoppable. The wind felt just as wonderful in his hair up here as it did when they galloped across solid ground, if not more so from the chill of the night sky and wide expanse before them. The trail had been fairly easy to follow, if sometimes tricky. Whatever or whoever it was creating it was travelling fast, taking sharp corners at major landmarks, and the path of snow below was starting to melt as Sven struggled to keep up.

They had to tread more carefully once they reached the big city, its lights making mindless flying dangerous. Neither of them was keen to have a repeat of their encounter a year back with some hunters. They had aimed to shoot them out of the sky. Kristoff shuddered at the memory as they landed atop a building. The loud noise and distinct whistle past their ears had scared him a lot. Warily he eyed the crowd on the street. Not many folk in this part of town, though still some groups of adults wearing garish outfits and being loud. The icy path he had followed had hopped off the building across the street to puddle in front of a store window.

He squinted at the sign above it, struggling to remember his letters. He hadn't used them in a while… Pugs and Does? Something like that he thought. Whatever it was called it looked closed, the dummies in the window bare of any clothes or produce. He stared at the puddle of frost and white powder a while, wondering where whatever had caused it could have vanished to. His consternation only grew as groups of adults trudged over the white covering, some stopping and obscuring his view of the front door. Did the thing responsible for this ice go inside the shop? Did they just stop making ice? Had the ice been powering their flight?

It wasn't till Sven shoved him with one of his antlers that he noticed something odd. His reindeer friend nodding towards the robed adults now facing the store window: One of them seemed to be talking to the mannequin therein. They weren't just talking at it, like he'd sometimes seen kids do ("Look at that loser with the antlered mongrel, wow." or "Hey statue of king George, I'm going to climb you!"), they were deliberately engaging it in conversation, arms waving in and out with descriptive gestures, pauses as the speaker chose their words and finally silence as they awaited the mannequin's answer, eyes glued to its blank face.

Kristoff's eyes had sparkled with wonder when the mannequin moved, nodding approval of whatever it had been told. The store window appeared to shimmer as the speaker sighed in relief, shoulders relaxing a touch. Stepping into the glass, he waved his two companions in, a large man holding up a slimmer one with a nasty gash over one eye. It wasn't long before the three had wandered into the building only to disappear, the store's display now looking as dusty and empty of life as before, the mannequin still once more.

So that's where the source of ice must have gone!  
>"Good job, Sven!" He hugged his reindeer tightly. "Now… How are we going to get in?"<p>

He didn't trust himself talking to the mannequin. It involved talking to people (even fake-people) and it risked him being confronted by the three who'd just gone in. He was used to hiding, skulking in shadows now. It was how he lived, how he survived. Besides, the mannequin might not let Sven in. Kristoff had visited enough stores to know that most frowned at the presence of furry creatures in their premises.

His friend pulled through once more, nuzzling his face towards the side of the red bricked building. It was a small alleyway, but it certainly looked worth investigating. Carefully the two leapt across to the roof opposite, examining the alleyway from above. There wasn't much to see. The building was a simple block, two small frosted windows built into the walls. There was a door at the back leading to a small car park. Cars in various stages of disrepair huddled together, the odd exception gleaming brightly with polish and wax. Kristoff pulled his tattered coat tighter to ward off some of the wind chill. He was feeling tired.

"Ah." A small noise brought his attention to a part of the wall further along. Light gleamed on metal as he spotted a fire escape ladder, grated landings punctuating each floor. The pool of light flickered, showing him the collection of potted plants and rocks accumulated on the highest platform. As he leaned out, he thought he could see a door made mostly of glass left slightly open. "Hey Sven, come here."

At his beckoning wave the reindeer approached, curious eyes examining the greenery below.  
>"Are you thinking what I'm thinking?"<p>

"Only if its let's get down there." Kristoff replied for the reindeer, his goofy voice accentuating the reindeer's happy nods.

"Alright let's do this!"

Hopping onto Sven's back for the brief glide down to the balcony, Kristoff found to his great delight that fate had indeed favoured him that night.  
>"There's the ice!" He whispered, hiding behind the frame of the door as he peered through the glass. A young girl was stood at the other entrance to the room. White coated the floor at her feet, faint snowflakes floating in and out of existence around her. She couldn't be much older than he was. Despite his excitement at finally finding the source of the magical ice trail, the young boy found himself frowning in confusion. The girl, with her near white blonde plait, looked so sad and scared. He wondered how anyone with such a wondrous gift could be anything but happy.<p>

His brown eyes shifted to the part of the room that held the young girl's attentions. A younger, smaller girl with red hair was asleep on some kind of examination table, a woman, her mother perhaps, holding onto her as a grey-skinned old man in a cloak of moss waggled his fingers. Wary of the moustachioed man behind the blond girl, he peered closer. Something seemed to be shimmering in the air above the red haired girl's head. He could make out images, pictures of snow and magic and winter landscapes superimposing themselves around playful tots.

The rest, as he'd heard some people say, was history. The ice-girl's family had left. The big rock on the balcony behind them had turned out to be Bulda, a rock person, daughter to the rock person in the room who was a lot shorter once he got off his stool. After questioning him a little, Gran Pabbie had given in, allowing Bulda to take him and Sven along as they travelled to this magical clearing full of friendly faces and fun. As he lay there against the sleeping Sven's fuzzy flank, Kristoff basked in the warm feeling of happiness he hadn't felt for a while, his mind wandering back to the dreams he'd just had of giant stone marbles and girls that could summon snowballs.

His dozing thoughts, however, were interrupted by the rising sound of hushed voices nearby.

"Gutten kan ikke bo." The syllables were foreign, the words making little sense, but still, Kristoff's ears puckered and he kept himself still, trying to make out what was being said. He became even more attentive when he heard Bulda mention his name in response. "Men Kristoff liker det her."

With a sigh the other voice switched to English, much for young Kristoff's relief.  
>"I'll check with the ministry in the morning, see if we can find the boy's family." There was great tiredness in Grand Pabbie's voice, and a sort of fatalism that the blond didn't like. "He deserves a home, Bulda, even if it is one he chose to run away from… Now if you'll excuse me, I need my rest."<p>

There was some grumbling in that foreign tongue again, a rumble and then the quiet returned. Kristoff wasn't reassured. He thought he had found a home, but by the sound of it, these people weren't going to take him in. He'd heard the word ministry before too, and he didn't like it either. Tears threatened to spill from his eyes as he rolled over. He clung to Sven for comfort, the reindeer shifting to accommodate his new position. Well if they didn't want him, he will just have to leave again. It wouldn't be the first time…

But not yet, Kristoff didn't want to leave. Not yet.

"Go, Kristoff, just go!" The man is shooing him out the window, his big burly arms shoving him with startling ease. "Grab Sven and run. Whatever you do, don't turn back!"

"But… Pa… What?"

"Go!" The sharpness of the command left no room for discussion. The tall parent's silhouette darkening as they left the window, sleeves rolled up for who knows what purpose. Obediently, the boy jogged down towards the stables, his sleepy mind slowly becoming aware of sounds that had no place in their dwelling in the woods. Shouts, explosions and what sounded like curses flew from the other side of their home.

The determined expression on his father's face still haunting him, he managed to still the urge to turn back, to intervene. He didn't like how angry his mother's voice sounded. He didn't want give her cause to shout at him in that way.

The reindeer in the stables were, of course, not oblivious to the chaos unfolding. It only took Kristoff a moment to decide to unbolt all the doors. The deer would know what to do. Letting them out would at least help them to panic less. He came to Sven's door last, the youngest of the lot. Kristoff quickly grabbed the small harness and put it on him, speaking words of reassurance that he didn't truly feel. Leading his young friend to the edge of the woods, he climbed on, tears in his eyes as he whispered the words "we've got to go."

He turned his head only once, upon hearing an almighty roar. The dark silhouette of a stranger was turned towards him, eyes wild and unfriendly, blood covered hand raising a wand that vibrated with power.

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><p>The sound of Sven's worried braying brought Kristoff back to reality with a jolt, but he was still disorientated. His pulse was fast and furious. His skin felt clammy. His mouth felt dry with his heart in his throat. The urge to bolt was strong, the shadow still looming in his mind. He couldn't move. He struggled as slowly his mind began to process what had happened. Nightmare, he'd been having a nightmare. He must have woken Sven up and oh no… No, no, no…<p>

He stilled as he realized what it was that was pinning him to the ground. With big bleary eyes, he turned to look up at the stone person hovering above him, one granite hand fixed to his shoulder as the other waved at some mist hovering above his head. Gran Pabbie, it was Gran Pabbie.

"What…" His voice croaked. "What are you doing?"

The old creature above him briefly turned weary eyes down to meet his own. There was only a momentary hesitation as he replied.

"I'm using troll magic."

Troll magic? Kristoff puzzled it over for a moment, his heart slowing as his mind detached itself from the dream world, focussing instead on the bizarreness of hearing the word troll. Didn't trolls live under bridges? Didn't they eat people?

It suddenly occurred to Kristoff that there was such a thing as people who ate people, and for every good reindeer there could be a bad reindeer. Surely for every bad troll, there could be a good one too?

"This… troll magic…" He said between hiccups. "Will… Will it make the bad dreams go away?"

A sad smile graced the old troll's face. The hand on Kristoff's shoulder squeezed reassuringly.

"I'll see what I can do."

The blond boy relaxed and smiled. He'll stay, if only a little while longer.

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><p><strong>(End part 2)<strong>

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><p><span>PS<span>: Saint Mungo's hospital for magical injuries' entrance is a "Purge and Dowse" clothes store under renovation in London. Which I had to look up.


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